By doing therapeutic exercises, patients in Fetterman’s situation can continue to make progress for many months, experts say.

Fetterman’s physicians have said his stroke caused deficits in something called auditory processing. That term may be confusing for laypeople, because it sounds as if it refers to hearing ability, not speech, said Brooke Hatfield, a speech-language pathologist who works for the American Speech-Language-Hearing Association (ASHA).

In fact, auditory processing refers to a host of brain functions that make both hearing and speaking possible — among them, recognizing sounds as speech, mapping them against known words, and formulating a response. These language networks in the brain are distinct from the pathways involved in critical thinking and cognition, Hatfield said.